Signs of sleep deprivation in children and adults:

An evidence-based guide

You may be very familiar with some of your own signs
of sleep deprivation. Besides the really obvious stuff--feeling tired
or drowsy--you may also show the following signs (Dement and Vaughan
1999):

Being slow to wake up in the morning; needing caffeine to “get going"

Having difficulty paying attention

Being quick to fall asleep (healthy sleepers may take 20 minutes or more to fall asleep)

Poor reaction times

In addition, you may become more emotional in response to disturbing images or events (Yoo et al 2007).

But what about your children? Like you, they show behavioral changes when they are sleep-deprived. But the signs of sleep deprivation can be harder to recognize. Babies can’t articulate their feelings, and, as I note below, some signs in older children may look deceptively like symptoms of hyperactivity attention deficit disorder.

Here I provide a guide to identifying signs of sleep deprivation for the whole family. Because adult signs are often the easiest to recognize, I start with an overview of adult signs of sleep deprivation. Then I cover babies and older kids.

For more help determining your children's sleep needs, see these articles on the sleep requirements of babies and older children.

According to world-renowned sleep researcher William Dement, the best
way to understand your sleep needs is to keep a sleep diary. To do
that, you rate yourself using the Stanford Sleepiness Scale (quoted here
from Dement and Vaughan 1999):

Feeling active, vital, alert, wide awake

Functioning at a high level, not at peak

Relaxed, not full alertness, responsive

A little foggy, not at peak, let down

Tired, losing interest, slowed down

Drowsy, prefer to be lying down

Almost in a reverie, hard to stay awake

Dement
recommends that you rate yourself every two hours during your waking
day for several days in a row. This will help you track your circadian
rhythms--when during the day you are at peak alertness, and when you
feel less wakeful.

According to Dement’s research (which has
focused on American subjects), well-slept adults should feel alert after
waking in the morning. They shouldn’t need special aids (like
persistent wake-up alarms, cold showers, caffeine etc.) to get going.

How alert should you be? You can test your alertness level—and other
signs of sleep deprivation--with this amusing (and valid) experiment online.

After awakening, alertness should gradually decline for the next 6 hours
or so, and then increase again until it reaches a second peak in the
evening (about 15 hours after awakening). After this peak is reached,
healthy adults should experience a sharp decline in alertness as they
become progressively more drowsy (Dement and Vaughan 1999)

If your
own pattern deviates from this norm, you might be sleep deprived. In
particular, feeling sleepy during the morning hours--and feeling as if
you could easily drowse off during times that are typically associated
with alertness--are classic signs of sleep deprivation.

Another
sign of trouble is feeling too restless or “wired" to sleep at bedtime.
There is evidence sleep deprivation causes elevated levels of cortisol
(the stress hormone) in the afternoon and evening (Copinschi 2005). In
addition, people suffering from insomnia have abnormally high levels of
cortisol at night (Rodenbeck and Hajak 2001).

Signs of sleep deprivation in babies

Babies may be pretty good at regulating their own sleep if they are
given plenty of opportunities for quiet time. But it’s possible for
things to go wrong. Read more about it in my article about signs of sleep deprivation in babies.

Signs of sleep deprivation in children

Kids are notoriously bad judges of their own sleepiness. In
experiments where 8-10 year olds were not permitted to sleep more than 4
hours at night, kids performed worse on cognitive tests. But (no
surprises here!) these same kids insisted that they were not sleepy
(Dement and Vaughan 1999).

Signs of sleep deprivation in kids include many of the same signs we see in adults. For instance, kids may

be harder to awaken in the morning

show greater difficulty concentrating

fall asleep spontaneously during the day (inadvertent napping)

"sleep in" on weekends (which suggests that they are making up for sleep lost during the school week)

Interestingly, lack of concentration and inadvertent napping are also
considered symptoms of attention deficit hyperactivity disorder (ADHD).

Other signs of sleep deprivation are also consistent with ADHD, including

hyperactivity (Kuhn et al 1999; Shur-Fen Gau 2006)

defiant behavior (Lavigne 1999; Shur-Fen Gau)

There is a growing body of research to suggest that some kids who have
been diagnosed with ADHD are really just sleep-deprived (Shur-Fen Gau
2006). But sleep restriction doesn’t always lead to ADHD symptoms
(Fallone et al 2001), and it’s possible that ADHD causes sleep
disturbances.

Children may also become more moody
when sleep-deprived. A recent study of healthy American elementary
school students links more intense emotionality with sleep problems (El
Sheikh and Buckhalt 2005).

Researchers monitored kids’ sleep with wrist
actigraphs (which can detect the physiological signs of sleep) and
parental reports. They found that the most emotional kids got the least
amount of sleep and had the highest number of night wakings (El Sheikh
and Buckhalt 2005).

Results like these seem to confirm our
everyday experience. But, as noted above, it’s not yet clear if sleep
problems are the cause or the effect of intense emotionality. Both may
be true, which case emotional kids may be prone to fall into a vicious
circle--emotional intensity making it hard to sleep, and sleeplessness
promoting greater emotional intensity.

Chronic sleep loss: When sleeplessness continues over the long-term

As these signs of sleep deprivation illustrate, poor sleep makes life
unpleasant. More worrying, however, are long-term problems for behavior, health, and cognition.

As noted above, kids who get
less sleep are more likely to show symptoms associated with ADHD. In
addition, they are more likely to be diagnosed with behavioral problems
in general (Lavigne et al 1999).

Perhaps most alarming is the idea that sleep deprivation in early childhood could impair cognitive performance later on.

A
recent prospective study tracked Canadian children from age 2.5 to 6
years (Touchette et al 2007). Researchers found that kids who got less
sleep overall—especially before 41 months—had higher rates of
hyperactivity and impulsivity at 6 years of age.

They also
performed lower on neurodevelopmental tests. Kids who were poor sleepers
at the beginning of the study performed worse at age 6, even if their
sleep times improved after age 3. This led the researchers to speculate
that there is a “critical period" in early childhood, when the effects
of sleep restriction are especially harmful (Touchette et al 2007).

Sleepless kids may not always show clear signs of sleep deprivation

In many cases, it’s pretty easy to identify kids with sleep problems.
But parents may have trouble recognizing the signs of sleep deprivation
in their kids. And it appears that many kids go undiagnosed.

An
experimental study of school-aged kids has shown that even kids who had
no reported sleep difficulties performed better on neurobehavioral tests
after they were given an extra hour of sleep (Sadeh et al 2003).

For
this reason, it makes sense to examine your child’s sleep
schedule--even if he doesn’t show obvious signs of sleep deprivation.
Good sleep practices will help ensure that your child gets the sleep he
needs. These practices include